This is a proposal for a longitudinal study of the fertility behavior of a sample of 1223 families over the period 1962 through 1977. The research will investigate the dynamic relationships between childbearing, marital instability, economic factors, wife's labor force participation, and sex role behavior and attitudes. Measures of the family's fertility behavior and plans obtained at five points in the family building process will be related to measures of the other variables similarly obtained. The following issues will be studied: 1. The nature of family size plans; how they change over time and their relation to completed family size. Also, an evaluation will be made of alternative measures of family size preferences and various indicators of unwanted pregnancies. 2. The effect of economic factors; including wife's labor force participation, on fertility behavior, including changes in fertility plans, and conversely, how various aspects of fertility, such as family size, premarital pregnancy, and unwanted births affect and change the family's economic position and the wife's participation in the labor force. 3. How do childbearing patterns, family organization, sex role attitudes, and economic forces affect marital instability, and what's the effect, in turn, of a marital dissolution on subsequent attitudes and behavior? 4. To what extent do sex role attitudes and the wife's participation in activities outside the home influence childbearing? How does childbearing and paid work influence subsequent sex role attitudes? These extensive dynamic data permit the issues to be evaluated using appropriate theoretical models which adequately specify the relationships. Such data will permit the analysis to more adequately disentangle the complex reciprocal forces.